Our increased understanding of the processes of diffusion and dissemination of effective prevention interventions has lead to keener recognition of the need for focus on the related but unique issues of implementation of effective interventions. Central among the issues to be addressed in implementation research is better understanding of the relationship between fidelity of implementation of the original intervention with replication (retention) of the effective outcomes of the original intervention. Over the past decade, the US-Bahamian team adapted an evidence-based program "Focus on Youth with Informed Parents and Children Together" from the CDC's Diffusion of Effective Behavioral Interventions (DEBI) portfolio to produce a 10-session adolescent HIV prevention program (with two additional follow-up booster sessions) entitled Focus on Youth in The Caribbean (FOYC) and a 1-hour parental monitoring intervention entitled Caribbean Informed Parents and Children Together (CImPACT)]. FOYC+CImPACT was evaluated through a randomized, controlled longitudinal trial involving 15 Bahamian elementary schools. Based on the effectiveness of FOYC through 36 months, the Bahamian Ministry of Education has decided to incorporate FOYC+CImPACT into the grade 6 curriculum throughout all 78 government elementary schools in The Bahamas, with follow-up booster sessions in grades 7 and 8. The proposed research will be conducted during the national implementation of FOYC+CImPACT. The research will enable us to refine and validate a definition of fidelity of implementation which can be used across the field of implementation science;to identify factors which impact fidelity of implementation;and, to test the relationship Following between fidelity of implementation and replication of intervention outcomes. pilot work among five elementary schools, the proposed implementation assessment will be conducted among the remaining 73 elementary schools in The Bahamas. Subjects will include ~ 300 grade 6, 7 and 8 teachers, ~ 140 principals and guidance counselors and ~4800 students in grade 6 at baseline and followed forward through grade 9. Through the use of observation forms assessing fidelity of implementation to be completed by trained observers, self-assessment forms to be completed by teachers, guidance counselors and principals assessing factors hypothesized to be related to fidelity of implementation, and a questionnaire assessing student outcomes (knowledge, skills, perceptions and behaviors), we will address: Aim 1: Assess the school level factors associated with fidelity of implementation of FOYC+CImPACT;Aim 2: Assess the classroom (teacher) level factors associated with fidelity of implementation of FOYC+CImPACT;Aim 3: Determine the relationship between delivery of FOYC+CImPACT with varying levels of fidelity and student outcomes including knowledge, skills, risk perceptions, intentions and behaviors;and, Aim 4 (secondary): Explore issues in the measurement of fidelity. PUBLIC HEALTH RELEVANCE: Our increased understanding of the processes of diffusion and dissemination of effective interventions has lead to keener recognition of the need for focus on the related but unique issues of implementation of effective interventions. Central among the issues to be addressed in implementation research are better understanding of what constitutes fidelity to the original intervention and further exploration of the relationship of fidelity with intervention outcomes. The public health and research communities have clearly articulated the importance of widespread diffusion of evidence-based prevention interventions in areas with high rates of HIV, such as The Bahamas. The CDC's Diffusion of Effective Behavioral Interventions (DEBI) program selects evidence-based HIV programs and prepares them for dissemination and adaptation in new surroundings. One of the DEBI programs, "Focus on Youth with Informed Parents and Children Together (FOY with ImPACT)", originally developed and evaluated in the United States, was selected by the Bahamian Ministry of Education for adaptation and evaluation in The Bahamas. As the developers of FOY with ImPACT, we worked closely with the Bahamian Ministry of Education to adapt the intervention so that it was appropriate for The Bahamas but remained true to the original intervention. The resulting adapted intervention, "Focus on Youth in The Caribbean and Caribbean Informed Parents and Children Together (FOYC+CImPACT)" was evaluated and found to be effective through three years of follow-up among Bahamian youth in grade 6 at baseline when the intervention was delivered. The Bahamian Ministry of Education is now preparing to implement FOYC+CImPACT throughout all of its elementary schools nationwide and desires to monitor fidelity of implementation during national implementation and to investigate factors that increase or impair fidelity of implementation, information which can be used both within The Bahamas in their ongoing efforts with national intervention implementation and throughout the globe as researchers seek to learn more about purposeful dissemination of effective interventions. Finally, because The Bahamas has already ascertained that the adapted intervention is effective in the new setting, the nation's public policy leaders wish to inform their efforts by determining if in fact fidelity of intervention implementation is associated with sustained intervention effectiveness. The opportunity to examine in a real world setting (rather than a controlled experimental setting) the degree to which fidelity of implementation of an HIV prevention intervention has been maintained during national implementation and to assess outcomes of an intervention (FOYC+CImPACT) that has been demonstrated to be effective in reducing HIV risk behavior under research conditions in the same setting (The Bahamas), will enable us to examine whether the presumed relationship between fidelity and effectiveness does exist. Given the resources being invested in dissemination of effective programs globally and the desire to maintain their effectiveness, the proposed research will be of considerable importance to The Bahamas, to the field of adolescent HIV prevention research, and to the vast field of global HIV fidelity of implementation which can be used across the field, to identify factors which impact fidelity and to describe the relationship between fidelity and outcomes. Given the resources being invested in dissemination of effective programs globally and the desire to maintain their effectiveness, the proposed research will be of considerable importance to The Bahamas, to the field of adolescent HIV prevention research, to the vast field of global HIV behavioral prevention, and to the emerging science of implementation research.behavioral prevention. The proposed research will enable us to refine and validate a definition of